I just read an extremely interesting post which explains an unwanted side effect of garbage collection by some Debian based systems. This cleanup process causes (maybe amongst other things) sessions to be cleared every 24 minutes, regardless of any ini setting you have set after the php.ini file is parsed (for example using ini_set() – if you are a symfony user, this is done during initialisation based on a setting in your factories.yml file).

You are only deleting and recreating a symbolic link, so it’s nothing too drastic that you should be worried about trying. Just log out and back in again after doing it and you should see “normal” shadows which you can go ahead and edit on the “window decoration” section of the Compiz settings.